Everyone is a bit different. That chart is a guideline, not an absolute. I sit in the 8-9' region from my 65" 4K and both 1080p (real 1080p like a bluray, and streamed conetent, not Comcast's pathetic attempt to declare something 1080p) and 4K content look awesome. Sure, there are those that will argue I need to sit closer to take advantage of the detail in 4K, to which I reply, poppycock. And the closer you get, the grainier everything is going to be. Place your seating where you think it looks best to you, not what some chart is telling you to do.
7.2.4 System: Display: Sony XBR-65X930D; Processing: Anthem AVM60
Mains: Paradigm Prestige 85F and 55C; Side / Rear Surrounds: Totem Acoustic Tribe III / Tribe I; Amplification: D-Sonic M3a-2800-7 (7ch. x 400w)
ATMOS: Definitive Technology DI8R; Amplification: Class D Audio SDS-470C (4ch. x 300w)
Subwoofers: 2 x SVS-SB13Ultras; Media: Oppo UDP-203, Pioneer CLD-59